The present invention relates to a hollow article made of an oriented thermoplastic, having a generally cylindrical body and a reentrant base, and particularly a bottle or similar container.
At the present time, the use of thermoplastics for the production of hollow articles, such as bottles for the packaging of liquids, is becoming increasingly widespread.
In order to increase the mechanical strength of these hollow articles, they are more and more frequently blow-molded under such conditions, especially such temperature conditions, as lead to orientation, preferably biaxial orientation in two mutually perpendicular directions of the macromolecules of the material of which the articles consist.
In order to increase the stability of these hollow articles in an upright position, it is known to provide them with a recessed, or reentrant, base because this type of base has good resistance to deformation, especially under the influence of internal pressure.
However, hollow articles with such a recessed base have an impact strength, especially at their base, which often leaves something to be desired. In particular, these hollow articles do not have good resistance to lateral impacts, which they may suffer if they are dropped accidentally or especially when they are transported by rail.